IRGen: bindOpenedElementArchetypesAtIndex() should use bindGenericRequirement()

Fixes rdar://problem/107852985.

Author: slavapestov

lib/IRGen/GenPack.cpp

@@ -954,6 +954,7 @@ void irgen::bindOpenedElementArchetypesAtIndex(IRGenFunction &IGF,
     return openablePackParams.contains(
         ty->getRootGenericParam()->getCanonicalType());
   };
+
   enumerateGenericSignatureRequirements(
       environment->getGenericSignature().getCanonicalSignature(),
       [&](GenericRequirement requirement) {
@@ -996,7 +997,18 @@ void irgen::bindOpenedElementArchetypesAtIndex(IRGenFunction &IGF,
     llvm::SmallVector<llvm::Value *, 2> wtables;
     auto *metadata = emitTypeMetadataPackElementRef(
         IGF, packType, conformances, index, MetadataState::Complete, wtables);
-    IGF.bindArchetype(archetype, metadata, MetadataState::Complete, wtables);
+
+    auto reqt = GenericRequirement::forMetadata(archetype);
+    bindGenericRequirement(IGF, reqt, metadata, MetadataState::Complete,
+                           SubstitutionMap());
+
+    assert(conformances.size() == wtables.size());
+    for (unsigned i : indices(wtables)) {
+      auto reqt = GenericRequirement::forWitnessTable(
+          archetype, conformances[i].getRequirement());
+      bindGenericRequirement(IGF, reqt, wtables[i], MetadataState::Complete,
+                             SubstitutionMap());
+    }
   }
 }
 

lib/IRGen/GenProto.cpp

@@ -3753,18 +3753,24 @@ void irgen::bindGenericRequirement(IRGenFunction &IGF,
   case GenericRequirement::Kind::WitnessTable:
   case GenericRequirement::Kind::WitnessTablePack: {
     auto proto = requirement.getProtocol();
-    auto conf = subs.lookupConformance(requirement.getTypeParameter(), proto);
+    setProtocolWitnessTableName(IGF.IGM, value, type, proto);
 
-    // FIXME: Remove this
-    if (conf.isPack() && isa<PackArchetypeType>(type)) {
-      assert(wasUnwrappedPack);
-      assert(conf.getPack()->getPatternConformances().size() == 1);
-      conf = conf.getPack()->getPatternConformances()[0];
-    }
+    if (subs) {
+      auto conf = subs.lookupConformance(requirement.getTypeParameter(), proto);
 
-    setProtocolWitnessTableName(IGF.IGM, value, type, proto);
-    auto kind = LocalTypeDataKind::forProtocolWitnessTable(conf);
-    IGF.setUnscopedLocalTypeData(type, kind, value);
+      // FIXME: Remove this
+      if (conf.isPack() && isa<PackArchetypeType>(type)) {
+        assert(wasUnwrappedPack);
+        assert(conf.getPack()->getPatternConformances().size() == 1);
+        conf = conf.getPack()->getPatternConformances()[0];
+      }
+
+      auto kind = LocalTypeDataKind::forProtocolWitnessTable(conf);
+      IGF.setUnscopedLocalTypeData(type, kind, value);
+    } else {
+      auto kind = LocalTypeDataKind::forAbstractProtocolWitnessTable(proto);
+      IGF.setUnscopedLocalTypeData(type, kind, value);
+    }
     break;
   }
   }

test/IRGen/bind_element_archetype.swift

@@ -0,0 +1,19 @@
+// RUN: %target-swift-frontend -emit-ir %s
+
+public protocol P {}
+
+public protocol Q {
+  associatedtype A: P
+}
+
+public func f<T: P>(_: T) {}
+
+public func foo1<each T: Q>(t: repeat each T, u: repeat each T.A) {
+  repeat f(each u)
+}
+
+public func foo2<each T: Q, each U>(t: repeat each T, u: repeat each U)
+    where repeat (each U) == (each T).A, (repeat (each T, each U)): Any {
+  repeat f(each u)
+}
+